Industrial compounds such as methylene chloride, dibromoethane, and butadiene are known carcinogens in rodents. These compounds are activated by conjugation with glutathione (GSH) and cause mutations in DNA by forming DNA adducts. The intermediates of this reaction are believed to be glutathione conjugates formed by glutathione S- transferases (GSTs). This proposal compares the ability of rat, human, and bacterial GSTs to form mutagenic DNA adducts with GSH conjugates in the presence of different haloalkanes and butadiene diepoxide. The proposed research will examine the genotoxicity of these compounds, the mechanism of activation by GST, the stability of the compounds, and the DNA adducts formed. The Ames test will be used to determine the mutagenicity of the various compounds when GST is being expressed in Salmonella typhuurium. Recombinant GSTs from human, rat and bacterial sources will be purified and used for in vitro assays to determine the mechanism of DNA adduct formation. Chemically synthesized intermediates of the GSH activation reaction will be tested for stability under various conditions and oligonucleotides will be used to test the formation of DNA adducts.